Most 1 year old babies go through between 7 to 10 diapers per day depending on how much they pee and how much they poop.
I changed my year old babies every 1 hour 30 minutes to 2 hours depending on how often they wet their diaper and how often they pooped.
Sometimes my 1 year old babies would poop 2 to 3 times per day and other times they would poop once per day.
The more they pooped and peed the more diapers they needed per day.
My 1 year olds had between 4 to 5 wet diapers per day but it can vary from baby to baby.
As long as you budget for around 10 diapers per day you should be okay with enough diapers.
It's better to have more diapers than you need than not enough diapers.
As they get older the toddlers will need less diapers per day and when my oldest was 2 he only needed a new diaper every 3 hours and sometimes only 4 hours.
So usually 4 to 5 diapers per day was enough for my 2 year old when he was 2.
Even now my current 2 year old goes through between 4 to 5 diapers per day and sometimes he doesn't need a new diaper until 4 hours later.
As the kids get older they wet less often and need less diapers.
At 3 years old my oldest kid could go 4 hours without needing a diaper change and he only needed 4 and sometimes only 3 diapers in a day.